The present invention generally relates to methods of determining enzyme activity involved in regulating metabolism. More particularly, the present invention relates to identifying cellular targets, enzymatic pathways, and enzymatic agents in order to treat pathophysiological disorders.
Enzymes are responsible for the metabolic needs, capabilities, and possibilities of living organisms. Enzymes are required in almost all chemical reactions in a cell and their activity determines which metabolic pathways can occur. While enzymes play a very important role in sustaining life, the malfunction of a single enzyme, through a mutation, deletion, etc., can lead to diseases, such as cancer or diabetes. Therefore, it is important to determine which enzymes are active in different disease situations.
Enzyme activity can be measured using either direct or indirect methods. Indirect methods include measuring the synthesis rate of its product or the consumption rate of its substrate as measured by mass spectroscopy, liquid chromatography, or via in vitro chemical assays. Direct methods include magnetic resonance imaging to measure in vivo enzyme activity. However, these methods are cumbersome and cannot be scaled to many enzymes or to different time points.
Accordingly, improved methods for determining enzyme activity are needed, in particular how enzyme localization reflects enzyme activity.